This invention relates to scaffolding, decking and shoring frameworks used in building construction.
Standard framing elements have been developed which can be used repetitively on construction sites in a variety of shoring applications. One of the most common shoring frame configurations comprises two vertical pillars joined together by a brace. That brace is usually made of a top and bottom transom and at least one oblique strut. The shoring frames are offered in a variety of sizes. Screw-jacks are mounted at both ends of the pillars for height adjustment.
The industry has strived to provide shoring frames with the highest strength-to-weight ratio, maximum convenience in mounting and dismounting complex frameworks, versatility of use, and extended durability. One of the most advanced examples of shoring frames is described in the Aluma Frame brochure published in 1987 by Aluma Systems Corp., of Toronto, Canada.
A shoring framework pillar of the prior art is illustrated in FIG. 1. The pillar 1 comprises a section of hollowed, tubular extrusion 2 having a generally square cross-section. The resistance of the pillar to bending forces due to axial or shearing loads has been improved by ribbing the four walls 3 in a variety of right angle folds. This tubular construction maximizes the load capacity of the pillar by distributing the weight on its peripheral wall. Screw-jack sleeves 5 are inserted into the top end 6 and the bottom end 7 of the pillar. The sleeves have an external diameter commensurate with the internal diameter of the pillar and an internal diameter commensurate with the standard two-inch (5.08 cm) diameter of screw-jacks 8. Each sleeve is capped with a plate shaped and dimensioned to match the transversal outline of the pillar. The plates 9 provides a bearing surface for the handles 10 of the screw jacks. The sleeves 5 are not permanently connected to the pillars, but must be provided and used with each screw-jack.
There is a need for an improved shoring frame pillar which would equal or exceed the load capacity of the pillars of the prior art, but would eliminate the need for top and bottom screw-jack sleeves. These screw-jack sleeves are added components which increase weight and complexity of shoring frames, and can be easily misplaced on building sites.